Detection and characterization of singly deuterated silylene, SiHD, via optical spectroscopy.

Singly deuterated silylene has been detected and characterized in the gas-phase using high-resolution, two-dimensional, optical spectroscopy. Rotationally resolved lines in the 00 (0)X̃(1)A(')→Ã(1)A(″) band are assigned to both c-type perpendicular transition and additional parallel, axis-switching induced bands. The extracted rotational constants were combined with those for SiH2 and SiD2 to determine an improved equilibrium bond length, rSiH, and bond angle, θ, of 1.5137 ± 0.0003 Å and 92.04° ± 0.05°, and 1.4853 ± 0.0005 Å and 122.48° ± 0.08° for the X̃(1)A(')0,0,0 and Ã(1)A(″)(0,0,0) state respectively. The dispersed fluorescence consists of a long progression in the Ã(1)A(″)(0,0,0)→X̃(1)A(')(0,ν2,0) emission which was analyzed to produce vibrational parameters. A strong quantum level dependence of the rotationally resolved radiative decay curves is analyzed.